Investigations on LED illumination for micro-PIV including a novel front-lit configuration

In this study, we provide a general investigation on micro-PIV with LED illumination. A number of improvements over previous LED-based systems are suggested, in particular, we present a novel front-lit configuration. As a demonstration of its versatility we have used this front-lit configuration to perform micro-PIV measurements around a 50 mu m squared pillar in a micro-channel with rectangular cross section, in both fluorescent mode and scattered mode. A comparison between the two modes is supplied, showing very good agreement between the respective velocity field results.